Plateful of Beta-Carotene: A Good Thing

Beta-carotene in food is good for you, but experts say getting it via nutritional supplements can be harmful

By Jeanie Lerche Davis
WebMD Weight Loss Clinic - Feature

Reviewed By Cynthia Haines, MD

Sweet potatoes, squash, pumpkin, carrots ? beta-carotene is easily identified in the rich oranges of fall vegetables -- and is certainly a good force against the evils of free radicals.

But beware of large-dose beta-carotene nutritional supplements, advise two leading scientific groups. Studies have pointed to potential problems, such as increased cancer risk.

The Mechanism

Like other antioxidants, beta-carotene has been credited as having disease-preventing powers. Antioxidants destroy harmful free radicals, a natural by-product of the body's metabolic processes.

Cigarette smoking, pollutants, and other chemicals are thought to bump up the number of free radicals, possibly causing some normal cells to turn cancerous. Beta-carotene and other antioxidants are said to "mop up" these free radicals, thus protecting cells and DNA from free-radical damage.

Exactly how beta-carotene supplements could boost cancer risk is not clearly understood. In high-dose supplements, beta-carotene is thought to "convert" from its antioxidant role; instead of destroying free radicals, it may actually increase their production.

Rulings Against Supplements

But don't get confused: Beta-carotene from food sources is outstanding for your health, Susan Taylor Mayne, PhD, professor of epidemiology and public health at Yale University School of Medicine in New Haven, Conn., tells WebMD.